http://bhs.minor9.com/biab/jazz/D/

could only get the cache on this site but they download, right click Save As:
http://bob.bmcadvies.com/biab/

I think they would just be midi but you could open them in Realband and put in RealTracks.

Edit: I thought they downloaded but didn't, there are midi files also you can use, just open in Realband and again, put in RealTracks.

More: http://www.igidigi.nl/biab/index.html